Drying machine



June 12, 1928.

H. A. HATFIELD DRYING MACHINE Filed April 23. 1927 2 Sheets-Sheet l HUBERTZAHATFIELD n 7Z3 AITORNE s June 12, 1928. 1,673,241

H. A. HATFIELD DRYING MACHINE Filed April 25. 1927 2 Sheets-Sheet 2 Fl 5 INVTE/NTOR,

HuBERTJwMFIEw BY 5 ATTOBN'E S Patented it... 12,1928.

UNITED STATES PATENT .oFF ca.

HU BERT A. HATFIELD, OF NEW GLASGOW, NOVA SGO'IIA, CANADA.

DRYING MACHINE.

Application filed April 23, 1927, Serial No. 186,041, and in Canada April 26, 1926.

This invention relates to new and useful improvements in drying machines, and the main object of the invention is to provide a machine which will be automatically controlled by the moisture content of the material passing therethrough.'

Another object is to provide a machine of the class stated which will be simple in construction and economical and eflicient in operation.

A further object is to provide a drying machine in which the material delivered therefrom will have practically the same moisture content.

In my invention, I provide a drying machine having an inlet pipe for a dryin agent which passes upwardly through the machine and an outlet pipeat the top there-.-

of. Pivotally mounted within the frame are a plurality 'of bafiies adapted to hold the material'under treatment and retard its passage through the machine. The baflles are provided with adjustable balancing means-to allow the machine to be adjusted to suit the class of material under treatment. The lowermost bafile is positioned above the drier outlet and is so balanced that when the material positioned thereon reaches a predetermined stage'of dryness, the baflie will tip and in tipping, will operate a switch which completes the circuit of an electrical suppl to a motor adapted to operate a pair of en less chains through suitable gearing. The chains are provided with projections, so poitioned that the tip all the upper baflles meet a time, an also open the end ofa feed chute. The chute is. provided with a regulating revolving bafile which is also controlled by the chain projections. A rotatin regulating baflie is mounted in the materia discharge end of the machine positioned below the lowermost bafiie.

In the drawings which show a form of my invention;

Figure 1 is a sectional side elevation of the drier in position before the material is tipped from the bottom'baflle.

Figure 2 is a side elevation of the drier with the side of the drier removed and the lowermost baflle tipped and placed back in position by the second lowermost baflie.

' Figure 3 is a plan view of the drier with the lowermost baflle and switch mechanism operated thereby.

Figure 5 is a partial side elevation of the mechanism shown in Figure 4.

Referring more particularly to the drawings, 11 designates the drier column or frame,

which is preferably, but not necessarily,

g the-hopper 14.- which is provided with an expanded portion 15 positioned near its outlet or discharge end 16. A shaft 17 extends from sideto side of the frame and positioned approximately in the centre portion of the expanded portion. The shaft 17 is rotatably mounted in suitable bearings 18 and secured to the shaft are a plurality of vanes or bafiles 19, adapted to regulate the passage of material through the drier feed chute. In the drawing, I have shown four such baflies, but this number may be increased or decreased according to the class of material under treatment, and the quantity it is deslred to pass through the machine. The shaft 17 extends through one side of the frame and secured to this extension is the ratchet toothed wheel 20, the teeth of which engagewith the end 21 of a pivotally mounted lever 22. Rotatablymounted on the shaft 17 is the arm 23, and pivotally mounted on the arm is the ratchetrwheel turning pawl 24 adapted to engage with the ratchet teeth.

The arm engages with an'extension 25 of I the lever 22 to hold the; end 21 in position. A counterbalance weight 26 may be provided on one end of theextension 25, to hold the end 21 out of engagement withthe teeth, during a certain period of .the operation of the machine. The end of the chute is closed I by a hinged door'27, which is provided with a counterbalance weight to hold it inthe closed position supporting a predetermined quantity of material within the chute and between'thedischarge end and the expanded portion 15.- Secured to the spindle 28 supever for opening the door in the manner hereinafter described. The lower end of the porting the door is an outwardly extending. the top of the drier and the hopper removed. I

Figure 4 is an enlarged side elevation of;

frame is provided with a discharge hopper 29, near the discharge end of which an expanded portion 30 is formed, and within said expanded portion is mounted a plurality of baflles 31, secured by any suitable means to a shaft 32, extending from side to side of the frame. The battles are so arranged that they prevent cold air from passing into the frame and yet allow free passage of the dried material from the frame. The shaft 32 is rotated by means of sprockets and chain driving means 32, driven from one of the tipping chain spindles 32*, hereinafter described. Between the feed hopper and the dischargehopper are a plurality of bafiles 33 secured to shafts 34 extending from side to side of the frame and rotatably mounted in bearings formed in or secured to the sides of the frame. It will be observed that each baflie extends from a point in close proximity to one side of the frame to a pointon the opposite side, but in close proximity to the shaft 34. The bafiies are arranged in zigzag formation, so that they retard the passage of the gases or drying agent through the,machine and are also positioned so that the material tipped from one baflle will be received by the bafiie immediately below it. Secured to each of the shafts 34 and positioned without the frame, are the counterbalance levers 35, and adjustable weights 36, which assist in counterbalancing the weight of each bafiie so that less power will be re- 'quired to operate thebafiles. Tipping arms 37 are secured to each shaft 34 and areso positioned that when they are raised by means, hereinafter described, they will raise the bafiie to the position shown in Figure 2, see the second lowermost bafiie. The lowermost or controlling baflie is not provided with a tipping arm, but is so constructed that the counter balance weight 36' will tip the bafile when the material held thereon has reached a predetermined state of dryness. The lowermost bafile is securedto a shaft 34 which extends from one-side of the machine and through the other side, and secured to the part 38 is the one-toothed ratchet wheel, or cam, 39. Rotatably mount ed on-the part 38 is the ratchet operating arm 40 whlch is provided with a ivotally mounted pawl 41. The free end '0 the arm 40 is secured to a lever 42 secured to the shaft directly above it, by means of the link 43. Also secured to the shaft extension 38 is the lever 44, the free end 45 of which is secured to one 'end ofa rocker arm, 46 by means of a flexible tension member 47. e

rocker arm operates a switch 48 which closes the circuit to a magnetically o erated switch 49 positioned in the wiring o' the motor 50. A main switch 51 may alsobe provided in the circuitto the motor, the circuit being shown diagrammatically in Figures 1 and 2. The other end 52 of the rocker arm is conpassing nected to one end 53 of a pivotally mounted lever 55, by means of a flexible tension member 56. The other end 54 of the lever 55 is positioned on the opposite side of the pivot 57 from the end 53. Extending from top to bottom of the frame and positioned on each side of the centre line of the frame and at one side thereof. are the endless chains 58, which pass around pulleys 59 secured to the spindles 60 and 32 The two uppermost spindles are connected together by means of a suitable train of gears 61, so that'when one chain is driven in the direction shown by arrow 62, the other chain will move in the direction shown by arrow 63. Secured to one of the spindles 60 is the sprocket toothed Wheel 64, which is driven by a chain passing around said wheel 64 and, similarly, toothed wheel 66 secured to ashaft 67 driven by a worm 68 and worm wheel 69 operated by the motor aforementioned. Each chain is provided with two projecting operating pins 70 positioned half the length of the chain from one another. Many modifications from that detailed herein may be made iii the construction of the device without departing from-the spirit of the inven- Um. I

In operation all the baflies are in the position shown in Figure 1, with the material to be treated mounted thereon. The door from the feed hopper is closed and supports a quantity of material equal to the amount held by the upper baflie and the feed chute regulating vanes prevent material from therethrough. A heated, or any other rm of drying agent is then fed into the machine through the inlet pipe at the bottom of the drier and through which it I passes to an outlet positioned at the top, its progress being retarded theretlirough by'the zig-zag mounting of the baflles, so that material mounted thereon may be subject to a maximum exposure to such drying agent. When the material on the lowermost bafile reaches a predetermined stage-of dryness, the counterbalance weight overcomes the combined weight of the material on said baflle and also the baflle itself, and tips the material into the discharge hopper which is provided with a rotating regulating device which controls the passage of material therethrough and, also, prevents entry into the drier of cold air or moisture which would decrease the efliciency of the drier. The bathe, in tipping, turns the shaft on which it is mountedand to which is secured the switch operating arm which closes the cir cuit to the motor through the relay or magnetic switch. The shaft, in turning, also carrice the tooth of theratchet wheel to contact with the pawl secured to the arm which is link connected to the baflie immediately above it. .The circuit, being closed to the motor, causes same to move the chains in the against the tooth of the cam to return the by the raising of the lever 22 and pulling.-

lowermost baflie to its normal or load re-,

ceiving position at the same speed that the second lowermost baffie is being tipped. This arrangement ensures a positive return of the lowermost bafile to its material receiving position. The chains carry projections which, in moving upwardly, contact with the baflle operating levers in such a manner that one is tipped and returned to its material receiving position, before the one above it is tipped.' When the uppermost baflle has been tipped and returned to its position, the door from the'feed hopperopens and deposits its load on the uppermost baflie. Whenthe door has closed, the feed control baffle is revolved to deposit a predetermined quantity of the material on the door. The,

rotating vanes are operated in the followin manner :The ratchet wheel is first released the end out of engagem'ent with the ratchet teeth. The arm to which the pawl is attached is then raised and the vanes are thus rotated. The rotating baflie or vanes in the discharge hopper is operated by the tipping chains. When the projection on the chain passes the last mentioned arm it drops back on to the extension 25 of the lever 22 and throws the end 21 into engagement with the teeth. The foregoing .part of the operation has been performed by the movement of one projection on, each of the operating chains. The other projection on the chain at the right hand side of the machine shown in the drawings, then comes in contact with thelever 25 and pulls on the rocker arm to break the circuit to the motor.

It will be seen from the foregoing, that a machine constructed and automatically controlled in the manner herein described provides a means for delivering material ,from the machine in such a manner that its molsture content remains constant. Thls' machine may. be used for drying wood chips, bark, sawdust, wastes from all plants in pulp and paper and also the lumber business. It may also be used for drying tan be easily regulatedtojfeed a predetermined amount of material at intervals to the drier may be employed. The discharge control- "ling mechanism may also be modified to suit the class of material under treatment.

Having thus described my invention, what I claim is 2- 1. A drying machine comprising a frame,

means for feeding material thereto, means,

for discharging material therefrom, means for feeding a drying agent thereto, an outframe, means for conducting a drying agent I to the frame, an outlet for said drying agent,

a pluralit, of ba'flles adaptedto retard the passage 0 the drying agent through the ma chine, said baffles being adapted to support the material thereon, and automatically controlled means for regulating the passage of material through the machine according to thechange in weight of the material as:

it is discharged from the bottom of the machine.

3. In a drying machine having means for feeding material thereto and discharging material therefrom, an-inlet and an outlet for a drying agent, bafiie means to retard the pro resses of the drying agent throu h s the mac inc, and also adapted to support t e material tobe dried thereon, a baflle pivota'lly mounted above the material discharging means, and means operating in conjunction with the last mentioned baflie to tip the materialthereonwhen the material reaches a predetermined state of dryness and means operated by the movement of the 'baflie to feed material into and through the machine.

4; In a'drier, a frame, a feed ho per, a discharge hopper, a plurality of ba es p votally mounted in the frame one above the Other, an inlet and an outlet for a drying agent, a control bafile pivotally mounted in the frame adapted to be tipped by a weight when the material thereon reaches a predetermined state of dryness, and means operated by the movement of the control baflies to successivel tip the baflle above the con- 'trol bafile an to open the feed chute.

.5.-In a drier, a frame, a feed hopper, a

regulating device within the feed-hopper to control the assage therethrough of the material to be ried, an outlet from the hopper,

a plurality-of pivotally mounted bafiies positioned below the feed hopper outlet and adapted to receive and retard the passage of V matepial therethrough, an inlet and an outmeans being adapted to first open the feed hopper and then operate the regulating device therein. I

6'. A drier according to claim '5, in which i the feed hopper controlling device comprises a plurality of vanes secured to and projecting outwardly from a shaft rotatably mounted in the hopper, and means secured to the shaft to rotate same when operated by the battle tipping means.

7. A drier comprising a frame, a feed-hop-' per'secured to said frame, ratchet controlled feed regulating means within the hopper, a plurality of pivotally mounted bafiles positioned below the outlet from the hopper and arranged one below the other in zig-zag formation' within the frame, a control bafile positioned below the lowermost aforementioned baflie, means to tip the control baflfle according to the state of the material under treatment, and supported thereby, means connecting the second lowermost and the control balfle to allow free tippin movement of the control battle but to bring said control bafiie back to material receiving position on tipping of the second lowermost bafile, means controlled by the movement of the control bafiie to successively tip all the baflies above it and to'operate the'feed regulating means in the feed hopper, and an inlet for a drying agent at the bottom of the drier and an outlet for a drying agent at the top of the frame.

8. A dryer according to claim 7, having the bafiie tipping means comprising a plurality of endless chains driven by a motor through suitable gearing, a plurality ofprojections on said chains adaptedto contact with levers moving in unison with the battles and switches in the circuit to the motor to close same by the tipping movement of the control bafile and means operated by the the control battle to operate the first mentioned means, means for feeding a drying agent to the machine, means for discharging the spent drying agent from the machine, and battle means for discharging the treated material from the machine.

10. A'method of controlling a drying machine consistingof regulating the vertical flow of material therethrough by the change in weight of the material being discharged from the bottom of the machine.

11. A method'of drying material consisting of feeding material to a machine, passing a drying agent through the machine, regulating the passage of the material in a substantially vertical manner through the machine. so that it @passes through successive stages of drying and automatically'controlling the movement of said material in the dryer by the change in weight of the material being discharged from the machine.

In witness whereof, I have hereunto set my hand.

HUBERT A. HATFIELD. 

